"Check Stop Lamp" - One brake light not on ?

I got this message and all bulbs are intact. Just the drivers side is out (the bulb is OK ) Regardless I replaced it. Fuses OK. The wiring diagram shows all brake lights controlled by relay so that's not it. I sprayed the contacts in the offending brake light socket and pried them out and still no luck. All fuses OK as well.

I am suspecting a local wiring issue that I cant see and considering replacing the harness for about $60. Cant imagine anything else.

All ideas greatly appreciated.